Transparent laminate, plastic lens for eyeglass and primer composition

ABSTRACT

A novel primer composition which does not need to be thermally cured at a high temperature after it is applied to a plastic substrate and a transparent laminate, for example, a plastic lens for spectacles, which comprises the above primer composition and has high impact resistance and high heat resistance even when a transparent anti-reflection coat is formed. This transparent laminate comprises a transparent plastic substrate and a coating film formed on at least one side of the plastic substrate by applying and curing a liquid primer composition which comprises (A) a self-emulsifiable emulsion of a linear polyurethane having a pendant carboxylic acid group and no crosslinked structure between polymer chains, (B) a sol of an inorganic oxide having a hydrophobic group on the surface, and (C) a compound having 5 to 9 carbon atoms and at least one hydroxyl group and at least one oxygen atom other than an oxygen atom constituting a hydroxyl group in the molecule.

FIELD OF THE INVENTION

The present invention relates to a transparent laminate, a plastic lensfor spectacles and a primer composition used for the production of thesame. More specifically, it relates to a transparent laminate havinghigh heat resistance and high impact resistance and a primer compositionwhich does not need to be thermally cured at a high temperature and issuitable for the production of a transparent laminate, for example, aplastic lens for spectacles.

PRIOR ART

Since plastic lenses are easily scratched, they are coated with a hardcoat. An anti-reflection coat is further formed on the plastic lenses bydepositing an inorganic substance to suppress reflection from thesurface in most cases. When a hard coat or an anti-reflection coat isformed on the surface of a lens, the impact resistance of the lensdeteriorates, whereby the lens is easily broken. To prevent this, aprimer is applied to the lens.

Meanwhile, to reduce the thickness of a lens, the refractive index ofaplastic lens substrate must be increased. When the refractive index ofa lens substrate is higher than 1.50, for example, the refractive indexof a hard coat or a primer must be made equal to that of the lenssubstrate in order to suppress an interference fringe generated by adifference in refractive index between the hard coat or primer and thelens substrate or a difference in film thickness between them. It isproposed to add an oxide having a high refractive index, such as TiO₂,to a hard coat or primer in order to increase its refractive index(refer to JP-A 07-325201 and JP-A 10-332902) (the term “JP-A” as usedherein means an “unexamined published Japanese patent application”).

After a primer is applied to a lens substrate, the primer must be heatedto be cured. When the lens substrate has a high refractive index and lowheat resistance, it must be cured at a low temperature for a long time,resulting in reduced productivity.

There is proposed a primer for obtaining a coating film by applying athermoplastic urethane polymer to avoid heating and evaporating asolvent (published Japanese translation of PCT international publicationNo. 8-505896 for patent application). However, when an oxide sol havinga high refractive index which is generally available on the market isadded to this primer to obtain a high-refractive index primer, theobtained coating film may become cloudy or the solution may gel.Therefore, the primer cannot stand long-time use. A primer whichcomprises an urethane elastomer and inorganic fine particles surfacetreated with a specific organic silane is also proposed (JP-A 9-291227).However, a transparent primer solution having long-term stability is notalways obtained from a combination of the above components.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a novel primercomposition which does not need to be thermally cured at a hightemperature after it is applied to a plastic substrate.

It is another object of the present invention to provide a transparentlaminate, for example, a plastic lens for spectacles, which comprisesthe above primer composition of the present invention and has highimpact resistance and high heat resistance even when a transparentanti-reflection coat is formed.

Other objects and advantages of the present invention will becomeapparent from the following description.

According to the present invention, firstly, the above objects andadvantages of the present invention are attained by a transparentlaminate comprising a transparent plastic substrate and a coating filmformed on at least one side of the substrate, wherein the coating filmis formed by applying a liquid primer composition comprising (A) aself-emulsifiable emulsion of a linear polyurethane having a pendantcarboxylic acid group and no crosslinked structure between polymerchains, (B) a sol of an inorganic oxide having a hydrophobic group onthe surface, and (C) a compound having 5 to 9 carbon atoms and at leastone hydroxyl group and at least one oxygen atom other than an oxygenatom constituting a hydroxyl group in the molecule, and by curing it.

According to the present invention, secondly, the above objects andadvantages of the present invention are attained by a liquid primercomposition comprising (A) a self-emulsifiable emulsion of apolyurethane having a pendant carboxylic acid group and no crosslinkedstructure between polymer chains, (B) a sol of an inorganic oxide havinga hydrophobic group on the surface, and (C) a compound having 5 to 9carbon atoms and at least one hydroxyl group and at least one oxygenatom other than an oxygen atom constituting a hydroxyl group in themolecule.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described hereinbelow.

The self-emulsifiable emulsion (A) used in the present invention is aself-emulsifiable emulsion of a linear polyurethane having a pendantcarboxylic acid group and no crosslinked structure between polymerchains.

The polyurethane is obtained by reacting a compound having a carboxylicacid group and two hydroxyl groups, an aliphatic diisocyanate and apolyester diol, polyether diol or polycarbonate diol each having twohydroxyl groups. A diamine may be coexistent in this reaction asrequired. In this case, an urea group is formed by a reaction betweenthe diamine and the diisocyanate. It should be understood that thelinear polyurethane in the present invention includes a polyurethanecontaining such an urea group. The amount of the urea group ispreferably 100 mol % or less based on the urethane group.

Examples of the compound having a carboxylic acid group and two hydroxylgroups include 2,2-bis(hydroxymethyl)-n-butyric acid and propionic acid.

Examples of the aliphatic diisocyanate include hexamethylenediisocyanate, 1,3,3-trimethylhexamethylene diisocyanate, isophoronediisocyanate, 4,4′-dicyclohexylmethane diisocyanate, hydrogenatedxylylene diisocyanate and hydrogenated diphenylmethane diisocyanate.

Preferred examples of the diamine include aliphatic diamines such asethylenediamine and hexamethylenediamine.

When a self-emulsifiable emulsion of a crosslinked polyurethane having acrosslinked structure between polymer chains is used in place of theself-emulsifiable emulsion of a linear polyurethane of the presentinvention, the coating film is readily whitened, the impact resistanceof an article coated with the coating film is not high, and the liquidprimer composition readily gels quickly. When a self-emulsifiableemulsion of a linear polyurethane having no pendant carboxylic acidgroup is used, a primer coat dissolves in a solvent for a hard coatsolution to be further applied to the coating film of this liquid primercomposition and contaminates the hard coat solution easily.

The polyurethane in the present invention preferably has a bisphenol Askeleton. When a polyurethane having no bisphenol A skeleton is used incombination with a SiO₂ sol to be described hereinafter, there will beno problem. However, when this polyurethane is used in combination witha sol of a composite oxide to be described hereinafter, the obtainedfilm may be whitened or the impact resistance of an article coated withthe coating film may lower. When a polyurethane having a bisphenol Askeleton is used in combination with composite oxide fine particles, thewhitening of the film can be prevented and high impact resistance can beobtained.

The above polyurethane preferably has a number average molecular weightof 100,000 to 1,000,000.

The self-emulsifiable emulsion of the above polyurethane can be producedby adding the above polyurethane to an aqueous medium containing a basiccompound such as an aliphatic amine or aromatic amine and stirring. Theabove polyurethane is emulsified to particles with diameter of 10 to 50nm.

The solids content of the self-emulsifiable emulsion is adjusted topreferably 50 wt % or less, more preferably 20 to 48 wt %.

The self-emulsifiable emulsion used in the present invention may beacquired under the name of Neo Rez (trademark) of Abisia Co., Ltd. orAdecabontiter (trademark) of Asahi Denka Kogyo K.K.

The self-emulsifiable emulsion preferably gives a coating film having anelongation of 240 to 500% and a 100% modulus of 190 kgf/cm² or more.

Since the coating film becomes hard by the dispersion of inorganic oxidefine particles to be described hereinafter into the resin, the resinpreferably has the above physical properties. A coating film having anelongation of more than 500% has high thermoplasticity and the beatresistance of an article coated with this coating film tends todeteriorate. When the elongation is less than 240%, the impactresistance tends to lower. When the 100% modulus is 190 kgf/cm² or more,excellent impact resistance and heat resistance are obtained.

The component (B) used in the present invention is a sol of an inorganicoxide having a hydrophobic group on the surface. The inorganic oxidefine particles of this sol increases the hardness, heat resistance andweatherability of the coating film. Inorganic oxide fine particlescontaining an oxide of Ti or Zr enhance the refractive index of thecoating film and serves to prevent the generation of an interferencefringe. The whitening of the coating film can be prevented by making ahydrophobic group existent on the surface of each inorganic oxide fineparticle.

Examples of the hydrophobic group include an alkyl group, alkyl groupsubstituted by an acryloxy group, alkyl group substituted by amethacryloxy group, alkyl group substituted by a glycidyloxy group andalkylene glycol group having an alkyl group at one terminal. Out ofthese, an alkyl group substituted by an acryloxy group and an alkylgroup substituted by a methacryloxy group are particularly preferredbecause a coating film having high stability is obtained. The whiteningof the coating film cannot be prevented when an amino group or an ureidogroup which is not a hydrophobic group is made existent on the surfaceof the inorganic oxide fine particle.

The inorganic oxide of the sol (B) is an oxide of at least one elementselected from the group consisting of Si, Al, Sn, Sb, Ta, Ce, La, Fe,Zn, W, Zr, In and Ti and the surface of the inorganic oxide fineparticle is modified by an organic silane compound represented by thefollowing formula (1) to have hydrophobic groups R¹ and R² on thesurface:R¹R² _(a)SiX_(b)  (1)wherein R¹ is an alkyl group which may be substituted by a methacryloxygroup or glycidyloxy group, R² is an alkyl group, X is a hydrolyzablegroup, a is 0, 1 or 2, and b is 1, 2 or 3, with the proviso that a+b=3.

The above oxide may be an oxide of a single element or a composite oxideof two or more elements. Examples of the inorganic oxide includesilicon, oxide, aluminum oxide, tin oxide, antimonyoxide, tantalumoxide,ceriumoxide, lanthanum oxide, iron oxide, zinc oxide, tungsten oxide,zirconium oxide, indium oxide, titanium oxide, composite oxide oftitanium oxide/zirconium oxide and composite oxide of titaniumoxide/zirconium oxide/silicon oxide. The composite oxide preferablycontains at least 50 wt % of titanium oxide. The inorganic oxidepreferably has a particle diameter of 1 to 100 nm.

Examples of the organic silane compound represented by the above formula(1) include methyl trimethoxysilane, γ-acryloxypropyltrimethoxysilane,γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldimethoxysilane,γ-acryloxypropylmethyldiethoxysilane,γ-methacryloxypropyltrimethoxysilane,γ-methacryloxypropyltriethoxysilane,γ-methacryloxypropylmethyldimethoxysilane,γ-methacryloxypropylmethyldiethoxysilane, trimethylchlorosilane,glycidyloxymethyltrimethoxysilane, α-glycidyloxyethyltrimethoxysilane,γ-glycidyloxypropyltrimethoxysilane andγ-glycidyloxypropylmethyldiethoxysilane.

The modification of the above oxide fine particle by the organic silanecompound may be carried out by hydrolyzing the organic silane compoundin the presence of the inorganic oxide particle and a catalyst in alower alcohol such as ethanol under the reflux of the lower alcohol. Asfor the ratio of the oxide fine particle to the organic silane compound,the organic silane compound is used in an amount of preferably 0.4 to2.5 parts by weight, more preferably 0.5 to 1.5 parts by weight based on1 part by weight of the inorganic oxide.

The inorganic oxide fine particle of the sol (B) is a SiO₂ fine particlewhose surface is modified by a hydroxy compound selected from the groupconsisting of a lower alcohol having 1 to 5 carbon atoms, propyleneglycol monoalkyl ether having 4 to 8 carbon atoms and ethylene glycolmonoalkyl ether having 3 to 8 carbon atoms to have a hydrophobic groupsuch as an alkyl group or an alkylene glycol group having an alkyl groupat the other terminal on the surface.

The surface modification of SiO₂ is preferably carried out by heatingthe SiO₂ fine particle in the presence of a catalyst in the abovehydroxy compound.

Examples of the lower alcohol having 1 to 5 carbon atoms includemethanol, ethanol, propanol, butanol and hexanol. The alcohol may belinear or branched. The alkyl group of the propylene glycol monoalkylether having 4 to 8 carbon atoms may be linear or branched and is analkyl group having 1 to 5 carbon atoms such as methyl, ethyl, n-propyl,iso-propyl, butyl or pentyl. Similarly, the alkyl group of the ethyleneglycol monoalkyl ether having 3 to 8 carbon atoms may be linear orbranched and is an alkyl group having 1 to 6 carbon atoms such as alkylgroup having 1 to 5 carbon atoms or a hexyl group.

The dispersant for the inorganic oxide fine particle having ahydrophobic group on the surface is water, alcohol or organic solventhaving compatibility with water. The above alcohol is a saturatedaliphatic alcohol such as methanol, ethanol, isopropyl alcohol,n-butanol or 2-butanol. Examples of the organic solvent havingcompatibility with water include cellosolves such as methyl cellosolve,ethyl cellosolve, propyl cellosolve and butyl cellosolve, propyleneglycol derivatives such as propylene glycol monomethyl ether, propyleneglycol monoethyl ether and propylene glycol monomethyl ether acetate,and esters such as methyl acetate, ethyl acetate and butyl acetate. Outof these, a lower alcohol (chain alcohol having 1 to 5 carbon atoms) ispreferably used. However, since the liquid primer composition gelsquickly by use of a lower alcohol as will be described hereinafter, theamount of the lower alcohol is preferably as small as possible. Thequick gelation of the liquid primer composition can be prevented byadding N-methylpyrrolidone to a lower alcohol solvent for the inorganicoxide sol or the liquid primer composition. However, when the amount ofN-methylpyrrolidone is large, it readily corrodes the plastic substrateso its amount must be small.

The compound having 5 to 9 carbon atoms and at least one hydroxyl groupand at least one oxygen atom other than an oxygen atom constituting ahydroxyl group in the molecule which is the component (C) to bedescribed hereinafter may be used as a dispersion solvent for theinorganic oxide fine particle as well.

The component (C) used in the present invention is a compound having 5to 9 carbon atoms and at least one hydroxyl group and at least oneoxygen atom other than an oxygen atom constituting a hydroxyl group inthe molecule. This compound has compatibility with water and a higherboiling point than the boiling point (100° C.) of water.

The compound is a monoalkyl ether of alkylene glycol, monoalkyl ether ofpolyalkylene glycol, monoacyl ester of alkylene glycol, monoacyl esterof polyalkylene glycol, 3-methoxy-3-methyl-1-butanol or diacetonealcohol. Specific examples of the compound include monoalkyl ethers (thenumber of carbon atoms of the alkyl group is 3 to 7) of ethylene glycol,monoalkyl ethers (the number of carbon atoms of the alkyl group is 1 to5) of diethylene glycol, monoacyl esters (the number of carbon atoms ofthe acyl group is 3 to 7) of ethylene glycol, monoacyl esters (thenumber of carbon atoms of the acyl group is 1 to 5) of diethyleneglycol, propylene glycol monoalkyl ethers (the number of carbon atoms ofthe alkyl group is 1 to 4) and propylene glycol monoacyl esters (thenumber of carbon atoms of the acyl group is 3 to 6).

By using the above compound (C), the liquid primer composition of thepresent invention can be existent as a stable solution for a long time.

When an alcohol having a low molecular weight with 4 or less carbonatoms is used as a solvent in place of the above compound (C), thealcohol permeates the inside of each particle of an urethane emulsionabruptly, thereby swelling the molecule and increasing the viscosity ofthe urethane emulsion with the result that the liquid primer compositiongels quickly disadvantageously.

The liquid primer composition comprising the above components (A), (B)and (C) of the present invention preferably contains 5 to 400 parts byweight (in terms of an inorganic oxide) of the component (B) and 50 to3,000 parts by weight of the component (C) based on 100 parts by weight(in terms of nonvolatilematter) of the component (A). 50 to 3,000 partsby weight of the component (C) includes a dispersant used for thecomponent (B). More preferably, the liquid primer composition comprises20 to 250 parts (in terms of an inorganic oxide) of the component (B)and 80 to 2,000 parts by weight of the component (C) based on 100 partsby weight (in terms of nonvolatile matter) of the component (A).

Since the lower alcohol preferably used as the dispersant for thecomponent (B) readily exerts a bad influence upon the stability of theliquid primer composition as described above, the amount of the loweralcohol is preferably 50 wt % or less based on the amount (50 to 3,000parts by weight) of the component (C).

Water is preferably used to adjust the viscosity of the liquid primercomposition, accordingly, the thickness of the coating film, and theamount thereof including water as a dispersant for the component (A) ispreferably 0.5 to 10 times the weight of the component (C).

The liquid primer composition of the present invention may contain aleveling agent, lubricity providing agent, ultraviolet light absorber,antioxidant, antistatic agent bluing agent and the like as required. Theliquid primer composition may further contain a crosslinking agent for apolymer and a catalyst for promoting a crosslinking reaction. Theleveling agent and the lubricity providing agent are particularlypreferably a copolymer of a polyoxyalkylene and polydimethylsiloxane ora copolymer of a polyoxyalkylene and fluorocarbon. They may be containedin the liquid primer composition in an amount of 0.001 to 10 wt %.

The liquid coating composition of the present invention is applied to atleast one side of a transparent plastic substrate to thereby provide thetransparent laminate of the present invention having a coating film.

The transparent plastic substrate is not limited to a particular kindand may be a polycarbonate, acrylic resin, polyurethane resin orepisulfide-based polymer. When the transparent plastic substrate is alens for spectacles, it is preferably a polyurethane resin,polymethacrylic resin, polyacrylic resin or episulfide-based polymer.

The application of the primer composition to the transparent plasticsubstrate may be carried out by dip-coating, flow-coating, spin-coating,spray-coating or the like. After application, the primer composition isheated at 50 to 90° C. for several minutes to 30 minutes to form a curedcoating film. The thickness of the coating film is preferably 0.1 to 5μm, more preferably 0.2 to 3 μm. When the thickness of the coating filmis smaller than 0.1 μm, the effect of improving impact resistance issmall and when the thickness of the coating film is larger than 5 μm,the hardness may be reduced after a hard coat is formed.

The transparent laminate of the present invention may further have ahard coat on the exterior surface of the coating film of the aboveliquid primer composition. The hard coat is a silicon resin-based film,for example, a film of a composition containing (D) a sol of aninorganic oxide fine particle selected from the group consisting ofoxides of Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr, In and Ti andhaving a particle diameter of 1 to 100 nm and (E) an epoxy-containingsilicon compound represented by the following formula (2) or ahydrolyzate thereof:R³R⁴ _(d)Si(OR⁵)_(3−d)  (2)wherein R³ is a group having an epoxy group and 2 to 12 carbon atoms, R⁴is an alkyl group or haloalkyl group having 1 to 6 carbon atoms, alkenylgroup having 2 to 6 carbon atoms, phenyl group or halophenyl group, R⁵is a hydrogen atom, alkyl group having 1 to 4 carbon atoms or acylgroup, and d is 0, 1 or 2.

The above sol of an inorganic oxide improves the hardness, heatresistance and weatherability of the hard coat. The inorganic oxide fineparticle containing an oxide of Ti or Zr increases the refractive indexof the hard coat to a value close to the refractive index of the aboveprimer coat to prevent the generation of an interference fringe.Examples of the above inorganic oxide include SiO₂, Al₂O₃, SnO₂, Sb₂O₅,Ta₂O₅, CeO₂, La₂O₃, Fe₂O₃, ZnO, WO₃, ZrO₂, In₂O₃ and TiO₂. Theseinorganic oxides are preferably in the form of a fine particle having aparticle diameter of 1 to 100 μm.

These inorganic oxides are surface treated with an organic silanecompound as required to enhance dispersibility in a solvent. The surfacetreatment may be carried out with an organic silane compound or ahydrolyzate thereof. The organic silane compound is preferably used inan amount of 20 wt % or less based on the inorganic oxide.

Examples of the organic silicon compound include compounds representedby the following formulas (3), (4), (5) and (6).

 R⁶ ₃SiX  (3)

wherein a plurality of R⁶'s may be the same or different and each anorganic group having an alkyl group, phenyl group, vinyl group,methacryloxy group, mercapto group, amino group or epoxy group, and X isa hydrolyzable group.R⁶ ₂SiX₂  (4)wherein R⁶ and X are as defined in the above formula (3), with theproviso that a plurality of X's may be the same or different.R⁶SiX₃  (5)wherein R⁶ and X are as defined in the above formula (3).SiX₄  (6)wherein X is as defined in the above formula (3).

Examples of the compound represented by the above formula (3) includetrimethylmethoxysilane, triethylmethoxysilane, trimethylethoxysilane,triethylethoxysilane, triphenylmethoxysilane,diphenylmethylmethoxysilane, phenyldimethylmethoxysilane,phenyldimethylethoxysilane, vinyldimethylmethoxysilane,vinyldimethylethoxysilane, acryloxypropyldimethylmethoxysilane,γ-methacryloxypropyldimethylmethoxysilane,γ-mercaptopropyldimethylmethoxysilane,γ-mercaptopropyldimethylethoxysilane,N-β(aminoethyl)γ-aminopropyldimethylmethoxysilane,γ-aminopropyldimethylmethoxysilane, γ-aminopropyldimethylethoxysilane,γ-glycidoxypropyidimethylmethoxysilane,γ-glycidoxypropyldimethoxyethoxysilane andβ-(3.4-epoxycyclohexyl)ethyldimethylmethoxysilane.

Examples of the compound represented by the above formula (4) includeddimethyldimethoxysilane, diethyldimethoxysilane, dimethyldiethoxysilane,diethyldiethoxysilane, diphenyldimethoxysilane,phenylmethyldimethoxysilane, phenylmethyldiethoxysilane,vinylmethyldimethoxysilane, vinylmethyldiethoxysilane,γ-acryloxypropylmethyldimethoxysilane,γ-methacryloxypropyldimethyldimethoxysilane,γ-mercaptopropylmethyldimethoxysilane,γ-mercaptopropylmethyldiethoxysilane,N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane,γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane,γ-glycidoxypropylmethyldimethoxysilane,γ-glycidoxypropylmethoxydiethoxysilane andβ-(3.4-epoxycyclohexyl)ethylmethyldimethoxysilane.

Examples of the compound represented by the above formula (5) includemethyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane,ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane,vinyl(β-methoxyethoxy)silane, γ-acryloxypropyltrimethoxysilane,γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimetboxysilane,γ-mercaptopropyltriethoxysilane,N-β(aminoethyl)γ-aminopropyltrimethoxysilane,γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,γ-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltrimethoxysilane,γ-glycidoxypropyltriethoxysilane, β-glycidoxypropyltriethoxysilane andβ-(3.4-epoxycyclohexyl)ethyltrimethoxysilane.

Examples of the compound represented by the above formula (6) includetetraethyl orthosilicate and tetramethyl orthosilicate.

Examples of the dispersant for the above sol of an inorganic oxideinclude water, saturated aliphatic alcohols, cellosolves, propyleneglycol derivatives, esters, ethers, ketones, aromatic hydrocarbons andother solvents.

The saturated aliphatic alcohols include methanol, ethanol, isopropylalcohol, n-butanol and 2-butanol; the cellosolves include methylcellosolve, ethyl cellosolve, propyl cellosolve and butyl cellosolve;the propylene glycol derivatives include propylene glycol monomethylether, propylene glycol monoethyl ether and propylene glycol monomethylacetate; the esters include methyl acetate, ethyl acetate and butylacetate; the ethers include diethyl ether and methyl isobutyl ether; theketones include acetone and methyl isobutyl ketone; the aromatichydrocarbons include xylene and toluene; and the other solvents includeethylene glycol, tetrahydrofuran, N,N-dimethylformamide anddichloroethane.

The amount of the inorganic oxide is, for example, 5 to 80 parts byweight, preferably 10 to 40 parts by weight based on 100 parts by weightof the sol.

The other component for forming the hard coat composition is anepoxy-containing silicon compound represented by the above formula (2)or a hydrolyzate thereof. The epoxy-containing silicon compound orhydrolyzate thereof is preferably contained in the hard coat compositionin an amount of 5 to 60 wt %.

Examples of the epoxy-containing silicon compound includeγ-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltrimethoxysilane,γ-glycidoxypropyltriethoxysilane, β-glycidoxypropyltriethoxysilane,γ-glycidoxypropylmethyldimethoxysilane,γ-glycidoxypropylmethyldiethoxysilane andβ-(3.4-epoxycyclohexyl)ethyltrimethoxysilane.

Examples of the dispersant for the hard coat composition includeglycols, aliphatic cyclic ketones, acetates, alcohols and othersolvents.

The glycols include ethylene glycol monomethyl ether acetate, ethyleneglycol monoethyl ether acetate, ethylene glycol monopropyl etheracetate, ethylene glycol monobutyl ether acetate, propylene glycolmonomethyl ether acetate, propylene glycol monoethyl ether acetate,propylene glycol monopropyl ether acetate, propylene glycol monobutylether acetate, ethylene glycol dimethyl ether, ethylene glycol diethylether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether,diethylene glycol dimethyl ether, diethylene glycol diethyl ether,diethylene glycol dipropyl ether, diethylene glycol dibutyl ether,propylene glycol dimethyl ether, propylene glycol diethyl ether,propylene glycol monomethylether, ethylene glycol monoethylether andethylene glycol monobutyl ether.

The aliphatic cyclic ketones include cyclohexanone,o-methylcyclohexanone, m-methylcyclohexanone and p-methylcyclohexanone.

The acetates include ethyl acetate, n-propyl acetate and n-butylacetate.

The alcohols include methanol, ethanol, 1-propanol, 2-propanol and1-butanol.

The other solvents include solvent naphtha and methyl ethyl ketone.

The hard coat composition may contain water in an amount 1 to 10 timesits theoretically stoichiometric amount to hydrolyze theepoxy-containing silicon compound of the above formula (2).

The hard coat composition further contains a curing catalyst.

Examples of the curing catalyst include chelate compounds, fatty acidsalts, primary to tertiary amines, polyalkylene amines, sulfonates,magnesium perchlorates and ammonium perchlorates. These compounds may beused in combination with an organic mercaptan andmercaptoalkylenesilane.

The chelate compounds include compounds containing Al, Zr, Co, Zn, Sn,Mn, V, Cu, Ce, Cr, Ru, Ga, Cd or Fe as a central metal and acetylacetone, di-n-butoxide-mono-ethyl acetate, di-n-butoxide-mono-methylacetate, methyl ethyl ketoxime, 2,4-hexanedione, 3,5-heptanedione oracetoxime as an coordination compound.

The fatty acid salts include metal salts of fatty acids such as2-ethyl-hexanoic acid, stearic acid, lauric acid, oleic acid, aceticacid, sebacic acid, dodecanoic diacid, propionic acid, brassylic acid,isobutyric acid, citraconic acid and diethylene amine tetraacetic acid.

More specific examples of the chelate compounds and fatty acid saltsinclude alkali metal salts and ammonium salts of carboxylic acids, metalsalts and ammonium salts of acetylacetone, metal salts of ethylacetoacetate and metal salts having acetylacetone and ethyl acetoacetateby coordination.

Further, the above primary to tertiary amines are preferably aliphaticamines, aromatic amines and aminosilanes. Examples of these aminesinclude polymethylene diamine, polyether diamine, diethylene triamine,iminobispropyl amine, bishexamethylene triamine, diethylene triamine,tetraethylene pentaamine, pentaethylene hexaamine, pentaethylenehexaamine, dimethylaminopropylamine, aminoethylethanolamine,methyliminobispropylamine, menthanediamine, N-aminomethylpiperazine,1,3-diaminocyclohexane, isophoronediamine, metaxylylenediamine,tetrachloroparaxylenediamine, methaphenilenediamine,4,4′-methylenedianiline, diaminodiphenylsulfone, benzidine, toluidine,diaminodiphenyl ether, 4,4′-thiodianiline,4,4′-bis(o-toluidine)dianisidine, o-phenylenediamine,2,4-toluenediamine, methylenebis(o-chloroaniline),diaminoditolylsulfone, bis(3,4-diaminophenyl)sulfone,2,6-diaminopyridine, 4-chloro-o-phenylenediamine,4-methoxy-6-methyl-m-phenylenediamine, m-aminobenzylamine,N,N,N′,N′-tetramethyl-1,3-butanediamine,N,N,N′,N′-tetramethyl-p-phenylenediamine, tetramethylguanidine,triethanolamine, 2-dimethylamino-2-hydroxypropane,N,N′-dimethylpiperazine, N,N′-bis[(2-hydroxy)propyl]piperazine,N-methylmorpholine, hexamethylenetetramine, pyridine, pyrazine,quinoline, benzyldimethylamine, α-methylbenzylmethylamine,2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethylol)phenol,N-methylpiperazine, pyrrolidine, morpholine,N-β(aminoethyl)γ-aminopropyltrimethoxysilane,γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,N-β(aminoethyl) γ-aminopropylmethyldimethoxysilane,γ-aminopropylmethyldimethoxysilane andγ-aminopropylmethyldiethoxysilane.

The above hard coat composition may contain a leveling agent, lubricityproviding agent, ultraviolet light absorber, antioxidant, antistaticagent, bluing agent and the like as required. The leveling agent and thelubricity providing agent are particularly preferably a copolymer of apolyoxyalkylene and polydimethylsiloxane or a copolymer of apolyoxyalkylene and fluorocarbon. They may be contained in the hard coatcomposition in an amount of 0.001 to 10 wt %.

The application of the hard coat composition to the primer coat of thetransparent laminate may be carried out by dip-coating, flow-coating,spin-coating, spray-coating or the like. After application, the hardcoat composition is heated at 90 to 120° C. for 1 to 24 hours to form acured coating film. The thickness of the coating film is preferably 0.5to 5 μm, more preferably 1.0 to 4.0 μm. When the thickness of thecoating film is smaller than 0.5 μm, the hardness may lower and when thethickness of the coating film is larger than 5 μm, the film may crack.

An anti-reflection coat may be further formed on the hard coat of thetransparent laminate of the present invention.

Reflection can be suppressed and transmission and weatherability can beimproved by forming the anti-reflection film consisting of a singlelayer or multiple layers of an inorganic substance on the hard coat.

SiO, SiO₂, Si₃N₄, TiO₂, ZrO₂, Al₂O₃, MgF₂ or Ta₂O₅ is used as theinorganic substance to form a thin film by vacuum deposition.

Prior to the formation of the hard coat, it is effective that the lenssubstrate should be subjected to a pre-treatment such as alkalitreatment, acid treatment, plasma treatment, corona treatment or flametreatment in order to improve its adhesion to the hard coat.

The transparent laminate of the present invention is particularlysuitable for use as a plastic lens for spectacles but it can also beused as safety spectacles which require impact resistance and atransparent plastic plate which requires impact resistance.

Effect of the Invention

According to the present invention, there is obtained a primercomposition which does not need to be thermally cured at a hightemperature and has stability for a longtime. There is also obtained atransparent laminate, for example, aplastic lens for spectacles, whichcomprises the above primer composition and has high impact resistance,high heat resistance, excellent weatherability, high hardness and highfilm adhesion even when a transparent anti-reflection coat is formed.

EXAMPLES

Examples of the present invention will be described hereinbelow.

Examples and Comparative Examples Examples of Preparation of Primer

(1) 127 g of diethylene glycol monobutyl ether (trade name of DaicelChemical Industry Co., Ltd.: Butyl Diglycol) and 507 g of distilledwater were mixed together, and 0.5 g of the Florad FC-430 of 3M Limitedwas added as a leveling agent to the obtained solution. 162 g of the NeoRez R-9679 (water dispersion of fine particles of a linear polyurethanehaving a pendant carboxylic acid group and no crosslinked structurebetween polymer chains, the linear polyurethane had no bisphenol Askeleton, solids content: 37%, elongation: 350%, 100% modulus: 406kgf/cm², manufactured by Abisia Co., Ltd.) was added to the above mixedsolution under agitation to prepare a uniform solution. Thereafter, 200g of a SiO₂ sol 1 (dispersed in 2-propanol, average particle diameter of10 nm, nonvolatile content of 30%, the surface of each SiO₂ fineparticle was made hydrophobic by a propyl group) was added to the abovesolution and stirred until a uniform solution was obtained, and theresultant was taken as a primer 1.(2) 119 g of diethylene glycol monobutyl ether (Butyl Diglycol) and 477g of distilled water were mixed together, and 0.5 g of the Florad FC-171of 3M Limited was added as a leveling agent to the obtained solution.200 g of the Adecabontiter HUX-350 (water dispersion of fine particlesof a linear polyurethane having a pendant carboxylic acid group and nocrosslinked structure between polymer chains, the linear polyurethanehad no bisphenol A skeleton, solids content: 30%, elongation: 450%, 100%modulus: 200 kgf/cm², manufactured by Asahi Denka Kogyo K.K.) was addedto the above mixed solution under agitation to prepare a uniformsolution. Thereafter, 200 g of a SiO₂ sol 2 (dispersed in n-propylcellosolve, average particle diameter of 10 nm, nonvolatile content of30%, the surface of each SiO₂ fine particle was made hydrophobic by anethylene glycol group having a propyl group at one terminal) was addedto the above solution and stirred until a uniform solution was obtained,and the resultant was taken as a primer 2.(3) A primer 3 was obtained in the same manner as in (1) above exceptthat 127 g of diethylene glycol monobutyl ether (Butyl Diglycol) usedfor the preparation of the primer 1 in (1) above was changed to 127 g ofdiacetone alcohol.(4) 142 g of ethylene glycol monobutyl ether (butyl cellosolve) and 568g of distilled water were mixed together, and 1 g of the SILWET L-77 ofNippon Unicar Co., Ltd. was added as a leveling agent to the obtainedsolution. 203 g of the Neo Rez R-9679 was added to the mixed solutionunder agitation to prepare a uniform solution. Thereafter, 83 g of aSiO₂ sol 1 was added and stirred until a uniform solution was obtained,and the resultant was taken as a primer 4.(5) 122 g of diethylene glycol monobutyl ether (Butyl Diglycol) and 487g of distilled water were mixed together, and 0.5 g of the Florad FC-430of 3M Limited was added as a leveling agent to the obtained solution.188 g of the Adecabontiter HUX-320 (water dispersion of fine particlesof a linear polyurethane having a pendant carboxylic acid group and nocrosslinked structure between polymer chains, the linear polyurethanehad a bisphenol A skeleton, solids content: 32%, elongation: 250%, 100%modulus: 360 kgf/cm², manufactured by Asahi Denka Kogyo K.K.) was addedto the above mixed solution under agitation to prepare a uniformsolution. Thereafter, 200 g of a composite oxide sol 1 comprising TiO₂,ZrO₂ and SiO₂ (TiO₂:ZrO₂:SiO₂=78.5:1.5:19.0, dispersed in methanol,average particle diameter of 10 nm, nonvolatile content of 30%, thesurface of each composite oxide fine particle was treated with a silanehaving a methacryloxy group-substituted alkyl group) was added to theabove solution and stirred until a uniform solution was obtained, andthe resultant was taken as a primer 5.(6) A primer 6 was obtained in the same manner as in (5) above exceptthat the same amount of a composite oxide sol 2 surface treated with asilane having a glycidyloxy group-substituted alkyl group was used inplace of the composite oxide sol 1 surface treated with a methacryloxygroup-substituted alkyl group used for the preparation of the primer 5in (5) above.(7) 129 g of diethylene glycol monobutyl ether (Butyl Diglycol) and 388g of distilled water were mixed together, and 0.5 g of the Florad FC-430of 3M Limited was added as a leveling agent to the obtained solution.342 g of the Adecabontiter HUX-320 was added to the mixed solution underagitation to prepare a uniform solution. Thereafter, 135 g of thecomposite oxide sol 1 was added and stirred until a uniform solution wasobtained, and the resultant was taken as a primer 7.(8) A primer 8 was obtained in the same manner as the primer 2 exceptthat 119 g of 3-methoxy-3-methyl-1-butanol was used in place of 119 g ofdiethylene glycol monobutyl ether (Butyl Diglycol) used for thepreparation of the primer 2 in (2) above.(9) A primer 9 was obtained in the same manner as the above primer 7except that 129 g of ethylene glycol monoacetate was used in place of129 g of diethylene glycol monobutyl ether used for the preparation ofthe primer 7 in (7) above.

Comparative Examples of Preparation of Primer

(10) A primer 10 was obtained in the same manner as the above primer 1except that 127 g of ethanol was used in place of 127 g of diethyleneglycol monobutyl ether (Butyl Diglycol) used for the preparation of theprimer 1 in (1) above.

(11) 119 g of diethylene glycol monobutyl ether (Butyl Diglycol) and 476g of distilled water were mixed together, and 0.5 g of the Florad FC-430of 3M Limited was added as a leveling agent to the obtained solution.200 g of the Superflex 150 (water dispersion of fine particles of acrosslinked polyurethane, nonvolatile content: 30%, elongation: 331%,100% modulus: 191 kgf/cm², manufactured by Dai-ichi Kogyo Seiyaku Co.,Ltd.) was added to the mixed solution under agitation to prepare auniform solution. Thereafter, 200 g of the SiO₂ sol 1 was added andstirred until a uniform solution was obtained, and the resultant wastaken as a primer 11.(12) 1 g of the SILWET L-77 of Nippon Unicar Co., Ltd. was added as aleveling agent to 625 g of methanol and 70 g of distilled water. 160 gof the Superflex 107 (water dispersion of fine particles of acrosslinked polyurethane, nonvolatile content: 25%, elongation: 250%,100% modulus: 85 kgf/cm², manufactured by Dai-ichi Kogyo Seiyaku Co.,Ltd.) was added to the mixed solution under agitation to prepare auniform solution. Thereafter, 133 g of the SiO₂ sol 3 (dispersed inmethanol, average particle diameter of 10 nm, nonvolatile content of30%, the surface of each SiO₂ fine particle was made hydrophobic by amethyl group) was added and stirred until a uniform solution wasobtained, and the resultant was taken as a primer 12.(13) A primer 13 was obtained in the same manner as the above primer 5except that the SiO₂ sol 4 (dispersed in water, average particlediameter of 10 nm, not surface modified, nonvolatile content of 30%, pHof 10) was used in place of the SiO₂ sol 1 used for the preparation ofthe primer 1 in (1) above.(14) A primer 14 was obtained in the same manner as the above primer 5except that ethanol was used in place of diethylene glycol monobutylether (Butyl Diglycol) used for the preparation of the primer 5 in (5)above.(15) 163 g of diethylene glycol monobutyl ether (Butyl Diglycol) and 650g of distilled water were mixed together, and 0.5 g of the Florad FC-430of 3M Limited was added as a leveling agent to the obtained solution.100 g of the Superflex 107 (the above crosslinked polyurethane) wasadded to the mixed solution under agitation to prepare a uniformsolution. Thereafter, 83 g of the composite oxide sol 2 was added andstirred until a uniform solution was obtained, and the resultant wastaken as a primer 15.(16) 6 g of the L-77 of Nippon Unicar Co., Ltd. was added as a levelingagent to 659 g of methanol. 158 g of the Superflex 150 (the abovecrosslinked polyurethane) was added to the obtained mixed solution underagitation to prepare a uniform solution. Thereafter, 177 g of thecomposite oxide sol 2 was added and stirred until a uniform solution wasobtained, and the resultant was taken as a primer 16.(17) A primer 17 was obtained in the same manner as the primer 5 exceptthat a cerium oxide sol not surface treated (dispersed in water, pH of3.5, average particle diameter of 8 nm, nonvolatile content of 30%,stabilized with acetic acid) was used in place of the composite oxidesol 1 used for the preparation of the primer 5 in (5) above.(18) A primer 18 was obtained in the same manner as the primer 5 exceptthat a composite oxide sol 3 surface treated with a silane having anamino group was used in place of the composite oxide sol 1 surfacetreated with a silane having a methacryl group used for the preparationof the primer 5 in (5) above.(19). A primer 19 was obtained in the same manner as the above primer 5except that a composite oxide sol 4 surface treated with a silane havingan ureido group was used in place of the composite oxide sol 1 surfacetreated with a silane having a methacryl group used for the preparationof the primer 5 in (5) above.

Examples of Preparation of Hard Coat

(1) 183 g of a SiO₂ sol (dispersed in water, average particle diameterof 10 nm, nonvolatile content of 40%, pH of 3) was weighed and 155 g ofγ-glycidoxypropyltrimethoxysilane was gradually added to the sol underagitation and cooling and further stirred for 1 hour after the end ofaddition. Thereafter, 512 g of 1-methoxy-2-propanol and 28 g of itaconicacid were added and dissolved in the obtained solution under agitationto prepare a uniform solution. Further, 122 g of a SiO₂ sol (dispersedin water, average particle diameter of 10 nm, nonvolatile content of30%, pH of 10) was added at a time and 0.4 g of the L-7001 (siliconesurfactant, manufactured by Nippon Unicar Co., Ltd.) was added as aleveling agent and stirred for 1 hour. The obtained mixed solution wasaged at 30° C. for 48 hours to obtain a hard coat solution 1.(2) 327 g of a composite oxide sol 5 comprising TiO₂, Fe₂O₃ and SiO₂(TiO₂:Fe₂O₃:SiO₂=82:0.7:18, dispersed in methanol, average particlediameter of 10 nm, nonvolatile content of 30%) and 110 g of distilledwater were weighed and mixed together. 169 g ofγ-glycidoxypropyltrimethoxysilane was gradually added to the obtainedmixed solution under agitation and further stirred for 1 hour after theend of addition. Thereafter, 387 g of 1-methoxy-2-propanol and 2 g oftetraethylene glycol monomethacrylate were added to the above solution.4 g of acetylacetone aluminum as a curing catalyst and 0.4 g of theL-7001 (silicone surfactant, manufactured by Nippon Unicar Co., Ltd.)were further added as a leveling agent and stirred for 1 hour. Theobtained mixed solution was aged at 25° C. for 48 hours to obtain a hardcoat solution 2.

Examples of Production of Coat Lens

After the above primer and hard coat solutions were prepared, they wereleft at room temperature for 3 days and applied.

The following two different types of plastic lens substrates A and Bwere prepared. A: lens of diethylene glycol bisallyl carbonate(refractive index of 1.50, obtained by thermally molding and curing theCR-39 monomer of PPG Co., Ltd.) B: lens of thiourethane resin(refractive index of 1.66, obtained by thermally molding and curing theMR-39 monomer of Mitsui Chem., Inc.)

After the above lens substrates were cleaned and dried, they were dippedin each of the above primer solutions at a lift rate of 10 cm/min, driedat room temperature for 5 minutes and heated at 50° C. for 10 minutes.After cooling at room temperature, they were further dipped in each ofthe above hard coat solutions at a lift rate of 15 cm/min, dried at roomtemperature for 5 minutes and heated at 120° C. for 60 minutes.

Further, ZrO₂, SiO₂, ZrO₂ and SiO₂ were vacuum deposited on thesesubstrates in this order to a thickness of λ/4 each sequentially to forman anti-reflection coat.

Examples of Evaluation of Performance of Coated Lens

The lenses having a primer coat, hard coat and anti-reflection coat wereevaluated by the following methods and their properties are shown inTable 1. adhesion test:

A cross hatch test was made in accordance with the crosscut adhesiontest JISK5400. That is, 100 squares were formed by cutting the surfaceof a film with a knife to draw 11 parallel lines at intervals of 1 mm inboth longitudinal and transverse directions, cellophane adhesive tapewas affixed to the cut film and then removed, and the number of squareswhich the film was not removed and was adhered to the substrates wascounted and expressed by %. film hardness test:

A film was rubbed back and forth 10 times with steel wool #0000 under aload of 1 kg to evaluate the hardness of the film according to thescratch of the film based on the following criteria.

5: not scratched at all

4: slightly scratched

3: scratched

2: badly scratched

1: scratched to the substrate

Measurement of Film Thickness:

Primer and hard coat solutions were applied to a glass plate under thesame conditions as described above and cured separately, part of thecoats was shaved off, and the thickness of the film was obtained fromthe level difference.

Impact Resistance:

A 16.32 g heavy steel ball was set at a height of 525 mm and dropped onthe convex surface of a lens by giving an initial speed thereto to makea break-down test by increasing the initial speed stepwise and repeatingdropping the ball in accordance with ANSI Z80.1. Impact resistance isexpressed as impact resistant collision energy (J) which is anintermediate value (mean value of 5 samples) between the amount ofcollision energy when the lens is broken or cracked and the amount ofcollision energy when the lens is not broken or cracked before that.According to FDA standards, this value needs to be 0.2J or more. Aplastic lens having a minus diopter and a center thickness of 1.0 to 1.3mm was used as the lens substrate.

Before measurement, the lens was left in a 20° C. atmosphere for 24hours and then a ball drop test was carried out at room temperature (20°C.).

Weatherability:

A xenon weather-o-meter weatherability promotion tester (black paneltemperature of 63° C., water was sprayed for 18 minutes every 2 hours,exposure intensity of 0.35 W/m² at 340 nm) was used to evaluate theappearance and adhesion of each lens after 240 hours of exposure.

Heat Resistance:

Lenses were left in a 60° C. atmosphere for 60 minutes and judged basedon the existence of cracking, a test was made on non-cracked lenses byincreasing the ambient temperature in increments of 5° C. until thelenses were cracked, and the upper limits of temperatures at which thelenses were not cracked are shown as heat resistance.

Stability of Solution:

The solution was stored at 20° C. for 3 months and the state of thesolution and the appearances of the coating films were observed.

The refractive index of the primer coat was 1.50 and the refractiveindex of the hard coat was 1.48 in Example 1, and the refractive indexof the primer coat was 1.65 and the refractive index of the hard coatwas 1.64 in Example 5.

TABLE 1 primer hard coat lens stability of primer thickness of thicknessof solution No. solution No. substrates solution primer coat (μm) hardcoat (μm) Ex. 1 1 1 A no change 1.5 3.0 Ex. 2 2 1 A no change 2.0 3.0Ex. 3 3 1 A no change 1.4 3.0 Ex. 4 4 1 A no change 1.8 3.0 Ex. 5 5 2 Bno change 1.3 2.0 Ex. 6 6 2 B no change 1.3 2.0 Ex. 7 7 2 B no change2.0 2.0 Ex. 8 8 1 A no change 2.0 3.0 Ex. 9 9 2 B no change 2.0 2.0C.Ex. 1 10 2 A gelled after 3 days — — C.Ex. 2 11 1 A gelled after 4weeks 1.7 3.0 C.Ex. 3 12 1 A gelled after 7 weeks 1.2 2.0 C.Ex. 4 13 1 Ano change 1.4 3.0 C.Ex. 5 14 2 B gelled after 3 days — — C.Ex. 6 15 2 Bno change 1.1 2.0 C.Ex. 7 16 2 B gelled after 4 weeks 0.4 2.0 C.Ex. 8 172 B gelled after 7 weeks 1.2 2.0 C.Ex. 9 18 2 B gelled after 7 weeks 1.12.0 C.Ex. 10 19 2 B gelled after 7 weeks 1.2 2.0 Ex.: Example C.Ex.:Comparative Example

TABLE 2 heat impact appearance hardness adhesion weatherabilityresistance resistance Ex. 1 satisfactory 4˜5 100% satisfactory 80° C.0.4 J Ex. 2 satisfactory 4˜5 100% satisfactory 80° C. 0.4 J Ex. 3satisfactory 4˜5 100% satisfactory 80° C. 0.4 J Ex. 4 satisfactory 4˜5100% satisfactory 75° C. 0.8 J Ex. 5 satisfactory 4˜5 100% satiafactory80° C. 0.8 J Ex. 6 satisfactory 4˜5 100% satisfactory 80° C. 0.9 J Ex. 7satisfactory 4˜5 100% satisfactory 75° C. 1.3 J Ex. 8 satisfactory 4˜5100% satisfactory 80° C. 0.4 J Ex. 9 satisfactory 4˜5 100% satisfactory75° C. 1.3 J C.Ex. 1 — — — — — — C.Ex. 2 satisfactory 4˜5 100%satisfactory 70° C. 0.1 J C.Ex. 3 satisfactory 4˜5 100% satisfactory 65°C. 0.1 J C.Ex. 4 whitened 4˜5 100% — — — C.Ex. 5 — — — — — — C.Ex. 6whitened 4˜5 100% — — — C.Ex. 7 whitened 4˜5 100% — — — C.Ex. 8 whitened4˜5 100% — — — C.Ex. 9 whitened 4˜5 100% — — — C.Ex. 10 whitened 4˜5100% — — — Ex.: Example C.Ex.: Comparative Example

1. A liquid primer composition comprising: (A) a self-emulsifiable emulsion of a linear polyurethane having a pendant carboxylic acid group and no crosslinked structure between polymer chains; (B) a sol of an inorganic oxide having a hydrophobic group on a surface of the inorganic oxide; and (C) a compound having 5 to 9 carbon atoms and at least one hydroxyl group and at least one oxygen atom other than an oxygen atom constituting a hydroxyl group in the molecule.
 2. A transparent laminate comprising a transparent plastic substrate and a coating film formed on at least one side of the substrate, wherein the coating film is formed by applying and curing a liquid primer composition comprising: (A) a self-emulsifiable emulsion of a linear polyurethane having a pendant carboxylic acid group and no crosslinked structure between polymer chains; (B) a sol of an inorganic oxide having a hydrophobic group on a surface of the inorganic oxide; and (C) a compound having 5 to 9 carbon atoms and at least one hydroxyl group and at least one oxygen atom other than an oxygen atom constituting a hydroxyl group in the molecule.
 3. The transparent laminate of claim 2, wherein a coating film of the self-emulsifiable emulsion (A) has an elongation of 240 to 500% and a 100% modulus of 190 kgf/cm² or more.
 4. The transparent laminate of claim 3, wherein the linear polyurethane of the self-emulsifiable emulsion (A) has a bisphenol A skeleton.
 5. The transparent laminate of claim 2, wherein the linear polyurethane of the self-emulsifiable emulsion (A) has a bisphenol A skeleton.
 6. The transparent laminate of claim 2, wherein the liquid primer composition comprises 5 to 400 parts by weight, in terms of an inorganic oxide, of the component (B) and 50 to 3,000 parts by weight of the component (C) based on 100 parts by weight, in terms of nonvolatile matter, of the component (A).
 7. The transparent laminate of claim 2, wherein the hydrophobic group is at least one member selected from the group consisting of an alkyl group, acryloxy group-substituted alkyl group, methacryloxy group-substituted alkyl group, glycidyloxy group-substituted alkyl group and alkylene glycol group having an alkyl group at one terminal.
 8. The transparent laminate of claim 2, wherein the inorganic oxide of the sol (B) is a fine particle of at least one oxide selected from the group consisting of oxides of Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr, In and Ti and the surface of the fine particle is modified by an organic silane compound represented by the following formula (1) to have a hydrophobic group on the surface: R¹R² _(a)SiX_(b)  (1) wherein R¹ is an alkyl group which may be substituted by a methacryloxy group or glycidyloxy group, R² is an alkyl group, X is a hydrolyzable group, a is 0, 1 or 2, and b is 1, 2 or 3, with the proviso that a+b=3.
 9. The transparent laminate of claim 2, wherein the inorganic oxide of the sol (B) is a composite oxide containing at least 50 wt % of titanium oxide.
 10. The transparent laminate of clam 2, wherein the component (C) is at least one member selected from the group consisting of monoalkyl ether of alkylene glycol, monoalkyl ether of polyalkylene glycol, monoacyl ester of alkylene glycol, monoacyl ester of polyalkylene glycol, 3-methoxy-3-methyl-1-butanol and diacetone alcohol.
 11. The transparent laminate of claim 2 which further comprises a hard coat on the coating film of the liquid primer composition.
 12. The transparent laminate of claim 11, wherein the hard coat is formed by applying and curing a composition comprising (D) a sol of an inorganic oxide which is a fine particle having a particle diameter of 1 to 100 nm of an oxide selected from the group consisting of oxides of Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, Zr, In and Ti and (E) an epoxy-containing silicon compound represented by the following formula (2) or a hydrolyzate thereof: R³R⁴ _(d)Si(OR⁵)_(3-d)  (2) wherein R³ is a group having an epoxy group and 2 to 12 carbon atoms, R⁴ is an alkyl group or haloalkyl group having 1 to 6 carbon atoms, alkenyl group having 2 to 6 carbon atoms, phenyl group or halophenyl group, R⁵ is a hydrogen atom, alkyl group having 1 to 4 carbon atoms or acyl group, and d is 0, 1 or
 2. 13. The transparent laminate of claim 11 which further has an anti-reflection coat on the hard coat.
 14. A plastic lens for spectacles which comprises the transparent laminate of claim
 13. 15. A plastic lens for spectacles which comprises the transparent laminate of claim
 11. 